PURPOSE: To provide a method by which metallic pipe covering optical fiber can be efficiently manufactured by performing welding in a large quantity of heat without causing the thermal degradation of optical fiber.
CONSTITUTION: In a manufacturing method of metallic pipe covering optical fiber constituted in such a way that a metallic belt M is bent in a pipe shape, and both side edge parts in the width direction of the metallic belt M are welded together, and a metallic pipe M is formed, and optical fiber F is inserted in the metallic pipe M through an optical fiber introducing pipe 20, the manufacturing method of the metallic pipe covering optical fiber is characterized in that a first inert gas supply pipe 21 is arranged in the optical fiber introducing pipe 20, and inert gas is flowed in.
AMANO TSUGIO
ONISHI TOSHIO
NIPPON KINZOKU CO LTD
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